Television system



Patented Mar. 9,

PATENT Aorf-'lola'.

TELEVISION SYSTEM Alfred N. Goldsmith,

Thaddeus N; J., vassignors New verk, N. Y., and

R. Goldsborough, Merchantville, to Radio. Corporation of America, a corporation of Delaware ,Application Novemer 1, 1932, serial No. 640,616

25 Claims.

The present invention relates' to a system by which independent series of signals may be com-- bined. In a particular form the invention is applied to television systems and is particularly diducing composite television pictures. f

In accordance with this invention a composite picture, by which is meant a picture in which 4the background is separately produced from the Vsorting to elaborate masking schemes o'r without the need of resorting to elaborate sets atI the point of transmission. In any theatrical presentation it is usually customary to develop for each change of scene to the observed a set and then to position the actors relative to the set so that the entire visible area may be subjected' to view by the audience. Similarly, it is usually customary in the operation of television apparatus 20 to produce the imagesignals representative of both the set and the subject simultaneously from the background and foreground for the purpose of transmission. However, in connection with television Where the action is extremely rapid and where the 'need of continuity of performance lwill become more'and more apparent as the art progresses, such procedure obviously 'indicates great and useless expenses to provide interesting programs with an adequate number of changes of scene to evoke in the mind of the observer' the same interest in the television transmission as is had in the usual motion picture presentation.

It is, therefore, anobject of the present invention to provide a system for producing comA posite pictures or television images wherein the foreground. and background action may take place at widely separated points yor may take place at two or more closely'adja'cent points .al-1. though the points are not in direct view offeneanother and the vaction at each point can be en? motion picture lms maygii desired, be used to ground action may take place separately and then be combined with the background to present ac.

rected to what may be termed a systemA for pro-'- foreground, is suitably transmitted without remonitor viewing system and then photographingv tirely separate from the action at the other point. z It is a further object of this invention toprovide a system of television by which ordinary) produce the backgrundand wherein the fore- (c1. ris- 6) 'foreground actions without resorting'to re-setting the studio to provide for. each separate action.

A further` object of this invention is to provide ways and means by which the background and foreground actions may be separately scanned and analyzedand by which the foreground action may serve to cause in the transmission an omission of transmittedsignals representativeof the background. In this manner the present invention is so constitutedv that the complete transmission will representvthe combination of foreground and background properly coordinated in sequence to produce at receiving points a single combined or composite picture or image representation representative of both the foreground and the background action or scene.

Another object of the invention is to provide a system by which it is relatively simple to photo'- graph composite pictures representing .combined foreground and background action. This may be done'in a convenientmannerby providing a theimage appearing thereupon. Y A further object of this invention is to produce a system -for transmitting television images in .whicnit is possible to use a single background set and to maintain the desired focus with variations in position of the foreground action without. motion of the background which will evoke inthe mind of the observer the' impression of moving background. Such actions and effects are producible, for example, by virtue .o f the factthat'whenever it is desired tol have 'the fore- .ground action move nearer or further away from @the point ofl scanning than for conditions of normal transmission the predetermined 'xed relv ative locations of the foreground and background actions may be suitably provided for withoutany' physical shift of either foreground `or back-f ground through a suitably arranged optical system a system 'for transmitting composite Piires which utilizes for the most part only the existing Vwith this known apparatus arrange Vnew vand "novel methods for coordinating the ac' i' l tions at av plurality of points for the combined' transmission of a single series of image signals representative oi' the action or scene at both the background and the foreground.

Other objects oi' the invention are, of course,-

Further `objects of the invention are toprovide' typesv of television transmission apparatus and.'

its construction and arrangement, and a system which fulllssubstantially the features now lacking in the art of producing television image signals which bear the same interest to the observer that the motion picture bears in the motion picture theatre or in connection with portable sound motion picture apparatus.

Still other and `further objects of the invention will become apparent and at once suggest themselves to those skilled in the art to which this invention is direct by reading the following specication and claims in connection with the accompanying drawing, wherein: i

Fig. 1 illustrates the transmitter end of the television system developed in accordance' with this invention; and

Fig. 2 illustrates also schematically a suggested frm of receiver apparatus for receiving the irnage signals transmitted from the transmitter of Fig. 1;

If reference is now made to the accompanying drawing forming a part of this disclosure, it will be seen that the background action, designated by the numeral I, and the foreground action, designated bythe numeral 3, are physically separated one from the other. This separation of background and foreground may, as above suggested, be a true geographical separation or may be a slight separation with the background action evenso close as adjacent to the foreground action, provided, of course, that the general features concerning the scanning operations to be hereinafter described are still maintained.

For the purpose of scanning the background and foreground and producing image signals which arek representative thereof we have provided two independently operable scanning systems generally designated as 5 and 1. These scanning systems are preferably in the form of cathode ray tube scanning devices and may be of the general type disclosed and set forth in the co-pending application of Vladimir K. Zworykin filed November 13, 1931, Serial No. 574,772 assigned to Radio Corporation of America. The details of these scanningtubes 9 and II have not herein been shown in detail. It should, however, be understood that each includes a lightsensitive plate electrode I2 adjacent to which is a'pick-up or grid-like electrode serving as an anode. The image of the illuminated background and foreground action is adapted to be projected upon the light-sensitive electrode -by way of a suitable optical system (not herein shown) so as to cause at each elemental area of the lightsensitive electrode a space charge which is proportionate in density to the illumination at the coordinated elemental area. If now within each cathoderay tube scanner 9 and I I a cathode ray is generated and caused to sweep the lightsensitive electrode within the tube by means of deflecting fields I2, I3, I4 and I5 of which the fields I2 and I3 provide motion in one direction 'mental areas can and the fields I4 and I5 provide motion of the beam in a direction transverse, and if the corresponding iields of each scanning tube are coordinated-'it can be seen that the cathode ray generated within the tubes 9 and II will simultaneously impinge upon coordinated elemental areas of lthe light-sensitive screen contained within each tube. In this manner the space charge coordinated with the particular elemental area on which the cathode ray pencil instantaneously impinges is released. Precision adjustment of thisA sirnultaneity of impact on coordinated elebe arranged by suitable electrical adjustment of the circuits associated 4with the tubes 9 and II as hereinafter described.

So controlled the released space charge may then be applied to the amplifiers I1 and I9 by way of conductors 2I, 2i and 23, 23 ,respectively so as to cause output currents to appear in the output circuits of the amplifiers which correspond in intensity or are proportionate to the intensity of the light impinging upon each elemental area of the light-sensitive electrode within the scanning tube., y

Let it now be assumed that the scanning tube 9 scans the background I and that the scanning tube II scans the foreground 3. It can be seen easily that at points where there is a ,scanning operation taking place 1n the foreground, as scanned by tube I I, it will usually be undesirable to permit output energy for transmission to result from the background scanned by the tube 9. If this were notso the receiving points would view the combined simultaneous scanning of background and foreground and the'produced electro-optical image signals at `the receiver would be ghost-like in appearance because both the background and foreground would be simultaneously observed with the result that the foreground action would appear unreal. normal conditions ghost-like,effects are not desired, but they can, when desired, be made use of, as will hereinafter appear.

To avoid ghost-like effects in the observed image there should be provided, under usual conditions, some means whereby in the absence of any foreground action, such as an absence of the actors 25, there will be no energy pick-up or substantially no energy pick-up in the scanning tube II. Similarly, where there is action taking place in the foreground there should be no energy pick-up representative of the background. Consequently, it is desirable to surround or enclose the entire foreground area with a material, preferably in the formfof a black matte 21 which is usually of a valvet-like material, from which there will besubstantially no reflection of light from an illumination source to the scanning tube II. However, where an object or subject is interposed between the black background or screen 21 and the scanning tube II so that the absorption of light is less than that of the matte 21 lightwill be reflected, preferably through a suitable optical system, to the scanning tube II. Image signals will then be produced in the output circuit 23 of the scanning tube II so as to be transferred for amplification to the amplifier I9.

At this time it is desirable to prevent any signals which represent the background from appearing in the combining amplifier unit 25 which Yis connected to both the background signal amplifier I1 and the foregroundsignal amplifier I9. Accordingly, the output from the amplier I9 representative of the foreground action, is directed not only to the combining unit amplifier 25 but alsn to a biasing amplifier 21. The biasing amplier 21, which may include any appropriate number of stages, has its output connected to the scanning tube 5 used for scanning the background. The scanning tube' 5, which is substantially a duplicate of the scanning tube 1 as above mentioned, has, however, provided therein a grid control element 29 to control, in accordance with the teachings ofl Nicolson Patent #1,470,696, for example, the intensity of the cathode rays from the source which are projected within the tube. Whenever signals representing foreground actionappear in the amplifier I9 these same sig- .Under obvious that no scanning action can result for:

nals canlbe caused to. block the cathode ray pen-` `cil within the tube 5 `or,in other words, can be' used to bias the cathode ray tube 5 to cut-off. With the tube 5 biased in this manner it is quite .the particular area of -the illuminated ph'otosensltive layer o r surface which corresponds to the' area at which the foreground action is projected upon the lightesensitive surface of the 0 scanning tube 1. .However, as soon as the scan- 1 ning .tube .'l has completed the scanning of the relatively high frequency and generates currents pictures along'a saw-toothl path, are -preferably v particular illuminated area the black background -adjacent the foreground action will, of course, prevent output signals from the'scanning tube 1 5 from appearing in amplifier I9.' The voltage upon the control grid 29 of the scanning tube 5 willV then immediately rise and the tube 5 will again .commence to scanthebackground action, with the result that operating voltages vrepresenting 0 background wiii besuppiied to the amplifierv i1 to be directed from' the output thereof to the combining unit 'amplifier 25 where the outputs of amplifiers-I1 and .I9 are assembled, p'ieced o'r .patched together.v

5 For the'purpose of insuring the synchronous movements of the cathode ray pencils within each scanning tube 5 and'lv a pair of synchronizing signal vgenerators have been provided to control jointly both tubes. These two synchronizing sig nal generators, 'offwhich the generator 3l is of a to move .the cathode ray pencil horizontally in each scanning tube along a' saw-tooth path, and the vertical synchronizing generator 33 which ningtube verticallyso as to frame properly the `in the form ofoscillators which have already been disclosed, for example, by the co-pending application of W. A. Toison, serial No. 608,460,

:tiled April 30, V1932 and assigned to Radio Corporation of Airu'erica,v or bythe co-pending ap-' plication of 'R."C. Ballard, Serial No. 584,943, filed January 16, 1932 also assigned to Radio 5 'Corporation of America. The synchronizing sig-- nals for moving the cathode ray pencil within each 'scanning'v tube are directed from the syn` --chronizing signal generator 3| for horizontalv vmovement of the -'ray to the deiiecting' coils I4 0 and I5, respectively, ofthe scanning tubes 5 and 1. Similar1y,-from the-vertical synchronizing V signal generator 33"the signals for controlling the vertical motion ofthe cathode ray pencil are i directed to the deflectingcoils I2 and' I3, re-

5spective1y, of the scanning tubes 5 and .1. It is to l be' understood that 'while the invention hasbeen illustrated as-utilizingelectromagnetic fields to control the movement of the cathode ray pencil 'within the scanning tubes, electrostatic' means may 'also beprovided, in which-case a sawtooth voltage wave would be generated inthe synchronizing signalgenerators 3l and 33 t'o -be applied 'to' the .electrostatic ray deflecting plates in contra st tothe saw-tooth current waveherein shown as developed vto produce the. electromagnetic `cathode ray deflection.- 1

' The combined output signals representative of the' combined background and foreground scanningaction are'. transferred `from the combining amplifier unit 25 to a modulator 35lto which is valsb'supplied. a carrier frequency as generated,

forfexample', in the oscillation generator 31. In

suitable manner thecarrier frequency is modu lated' by the output signals from thecombining 'lli-amplifiery unit 25. The modulated carrier freservesto move the cathode ray within each scan' quency signals are thensuitably amplied inthe transmitter amplifier 39 and transmitted .to geographically'spaced points of reception by Way of the radio transmission link conventionally designated by the antenna 4I or by way of a wire line or network transmission where desired.

A portion of the output from the synchronizing signal generators-3l and 33 for producing the horizontal -and Vertical deflection of the cathode ray pencil within the scanningtubes 5 and 1 is also supplied by way of suitable conductors 43 and 45' to themodulator unit 3.5 through an ampliiier 41 whichcontains one more or less stage,

' for example, of amplification than the combined 'reach an amplitude value suiiicient to overcome a predetermined and established bias on the amplifier unit 41. In this manner it is' quite apparent that the signals transmitted from the transmitting means 4I consist of image signals for a .time period corresponding to the timerequired to movethe cathode ray pencil Within each of Vthe scanning tubes from left to right, for. ex-

ample, of one elemental strip ofthe object areas I and 3.

` These imagesignals are 'then followed by a synchronizing signal indication which is pro- "duced 'during the time period required to cause the cathode ray pencil within the scanning' tubes' f5 and 1 to sweep back from right to left across, one elemental strip of the object areas I and 3,

after which the same preceding sequence is rec peated-` again and again.

Under certain circumstances, as for example when the actors 25, for example, appearing in the foreground 3 wear dark colored clothing, it has been found expedient to utilize' a highly reflecting back-drop for the foreground instead ofthe black velvet drop hereinbefore described. In such event, the connections to the bias amplie'r 21, and the further connections in the system, are so arranged that maximum output from the tube II causes 'the tube 5 to become inoperative and any output from the said tube II less than maximum, permits the tube 5 to vtransmit a background signal. Inasmuch as the connections necessary to' practice this modification of my Ainvention will be obvious to .those skilled in the art, they have not been illustrated in detail.

To receive the signals transmitted from the i 4transmitting means 4I a suitable receiver 49 is provided from which the signals are suitably amplliied in an amplifying means 5I and supplied' to theV detector 53 to which is also supplied energy from a local oscillator 55. In the output of the 'detector 53'there appear intermediate frequency signals which are suitably amplified in the intermediatefrequency amplifier 51 and directedto a second detector 59. The output signals from the detector 59 'are then suitably amplied in an ampliiierl unit 6I. As has already been explained in co-pending application of W. L.A Carlson, Serial No. 583,193, filed December 26, 1931, assigned to4 Radio Corporation of America', the picture signals l Vappearing in the output of amplier 5 I are ampliiied to a 'still further degree' by way of picture signal amplifier 634 and are then supplied across the grid cathode circuit of a cathode ray viewing tube 65. The tube 165. is vprovided with a fluorescent end wall 61. The impressed signals serve to control the intensity of the observable or. luminous effects produced upon the tube fiuorescent end wall 61 in accordance-with the teachings of Nicolson Patent #1,470,696, although l it is, of course, obvious that other forms of control of the effective intensity of the cathode ray could be substituted without involving invention and without departing from the spirit and scope of the present disclosure.

15 The synchronizing nsignals are suitably separated and supplied by way of conductors 69 and 1| to the horizontal synchronizing signal generator and the vertical synchronizing signal generator 13 and 15 respectively. The synchronizing 20 signal generators 13 and 15 are preferably of the general form suggested by the above mentioned application of W. A. Tolson, Serial No. 608,460,

although, here again, other forms might be substituted, such as, for example, the form shown in the above mentioned application of W. L, Carlson, so that'the cathode ray pencil 11 produced Within the viewing tube 65 is controlled both as to its horizontal and vertical positions by means of the defiecting fields 19 and 8l respectively, and

30 the observable eects produced by the cathode ray pencil 11 impinging upon the fluorescent screen 61 is an electro-optical image representation of the combined foreground andl background object areas l and 3 viewed by the scanning 'tubes 1' and 30 5, respectively.

. If now it is desired to provide for rapid changes 4 rapidly toward the viewing tube or to move rapto maintain in the foreground action fixed but to produce the effect of rapid motion with respect to the background, each of the scanning tubes 5 and 1 may have as a part of the optical system 45 (not specifically shown herein) by which the light from the object areas l and 3 is directed to. the light-sensitive electrode of the scanning ltubes, a so-called Zoom lens system of the general type shown and described in considerable detail in the article by Messrs. Warmisham and Mitchell which appeared in The Journal of the Society of Motion Picture Engineers, vol. IXIX, No. 4, for October 1932, pages 329 to 339, inclusive. AIt should be noted that when the Zoom lens is 55 used the lenses coordinated with each scanning tube 5 and 1 should be mechanically coordinated one with the other under usual conditions so as to maintain always the proper focus.. Furthermore, if it is assumed that the scanning tubes are 60 arranged at'one fixed location and that at a. predetermined distance from each tube there is the separate foreground and background object areas and that, for example, the foreground action moves nearer to the foreground scanning tube `idly away from the viewing tube, or if it is desired and the background, of course, does not change,-

"ghost-like effects, already mentioned, the biasing amplifier unit 21 may be so adjusted that signals directed thereto from the foreground signal amplifier I9 will not serve to bias to complete cut-off the scanning tube -5 but rather will serve only to reduce the amplitude of the output signals from the background scanning device 5 so that 'the combined signals appearing in the combining amplifier unit 25 for related and coordinated areas of the background and foreground simultaneously scannedby the scanning tubes 5 and 1 will be the combined light effect influencing each.v scanning tube, with the intensity of the signals resulting from any one scanning tube however usually diminished or reduced in intensity.,

In the operation of a system of the general type hereinabove described, the first condition usually to be encountered is a condition where there is no action in the foreground; secondly the condition should be obtained wherein the foreground which is assumedfor purposes of illustration, to be a black matte, such as velvet in the form of a shade box, which is to be illuminated to the fullest extent which the action will require. At this time the biasing amplifier 21 should be adjusted until the background scanning tube 5 just operates completely. This.l condition is the test f to determine the'sensitiveness of contol of the system to select automatically the separate image signals.

To provide for checking this adjustment it is usually desirable to increase very slightlyA thev foreground illumination. If proper adjustment of the biasing amplifier 21 has been made this increase in illumination of the foreground Acompletely wipes out the background scanning ef- .fects from the output signals. At this time it may be necessary to adjust slightly the biasing amplifier 21 which controls the control grid of the scanning tube 5 in order that the resultant combined signal from the scanning tubes 5 and 1 may appear in the proper relationship and intensity in the combining amplifier unit25, After these adjustments have been made the originally assumed maximumillumination for the foreground should be re-established and the operation of the system should be maintained with as 4 lillumination of the foreground, permit signals of varying intensity according to the particular type of Veffect desired to appear in the output of the scanning tube 5 for the background.

Where it is desired to reduce the eye strain from excessive illumination of the foreground action it may be desirable to substitute for the black velvet 21, .assumed for the foreground, a. red velvet, under which condition the actors 25 willuse green make-up and garments and green illumina- ,tion will be supplied. The light-sensitive photocells or photo-sensitive areas of the scanning tube 1 will be sensitive to green or covered by appropriate green light filters in order that use may be made of the so-called complementary black vin i,

contrast to the true black.

It should be noted that Ythe present invention,

may be used also -in any other art where it is necessary to superpose one series of energy impulses upon another and at the samel time to diminish or extinguish one series of impulses during the One of the particular elds i in' which such a system 'would be quite useful is `presence of another.

I background during the dialogue.

In addition, it should be understood that any suitable form of scanning device may, where desired, replace the cathode ray tube scanning system. Such types of scanning devices which might 20 be used in' alternative constructions include the so-called Nipkow disk, with or without lenses; the rotary-Weiller Wheel; vibratory mirrors; multispiral and shutter disk combinations; and, in general, any and all types of television scanning devices.

Also, where the background is moving continuously it is frequently desirable to provide a systernby which the actors can view the scene providing the background eiect. This may be provided by arranging the foreground and background areas I. and 3 so that they face toward each other so that the actors in the foreground can always view directly the instantaneous backupon a separatearea Awitliintlie view of the. actors but out of view of the scanning medium for foreground action. In this manner the foreground action may at times be made easier for 40 the actors 'and better coordination may besecured. I

In some instances it may be found desirable to monitor the combined signals representative of foreground and background. For this purpose a monitor image reproducing system 36 may 1 be controlled by the signals appearing in the combining amplier 25 output circuit which will produce on .the monitor, assuming that a cathode `ray monitor tube is used, varying intensity electro-optical image effects properly coordinated with foreground andbackground. The monitor image must also be controlled as 'to its instanta-A neous position on the image reproducing device A by means of the synchronizers for each view scanning tube lin a manner similar to the control produced upon the tubes 5,'1 or 65 by the synchronizing signal generators 3| and 33.

"A further advantage of the monitor imageis lthatfit may beeasily photographed toi produce a 'inotion picture record, for example, bf the composite-scene representative of both-foreground and background. In this manner motion. pic-4 tures of a most unusual type, which later can be transmitted or projected in WeILknoWn manner, 'n 6.5 canbe produced. Such motion pictures whichground a`great conflagration and then by ways' and means herein disclosed have 4the actor appear as if actuallyinthe origins as above described, is not limited to television but actually exposing the artist to a .Furthen in many instances i desirable to form objects inv tl such manner that the light re istics of the .entire object -areas the background. The scannin be unable to see or disting from -the background with. a

actors in the foreground may around the objects so as to ma picture more realistic.

Fade-in and fade-out scene desirable in the viewed composi fade-ins and fade-outs may be background and foreground scel transmission may readily be a the apparatus'lherein disclose several foreground and backgro vices in parallel and under tl single controlling source. Eact would then scan an independen normal conditions only'one for background scanning device wc with the combining amplifier u when a fade-out from one scan fade-in to another scanning de he background or foreground i is desired the action may be desired or known type of fade apparatus,l such, for example,

` by the copendin'g application o` smith, Serial No. 475,188, filed ground eect, or, where desired, the. background v 35 may be projected ineither full or reduced size and assigned to Radio Corporal Many other modicationsan invention and application to ol will, of course, become apparer fin the art and itis therefore invention shall be construed in; read upon ,all modications si within the spirit and v scope o appended claims wherein it is sired to secure by Letters Paten '1. A system of composite vte ing means rfor producing 4twc signalsby simultaneously ai scanning Vat least two objectpatching together the series sentative of the two object ai means fornullifying the signa of one of the series of signals of the signals of the other s .periods when signals in the co produced simultaneously with i trolling series.

2. In-a system for producii constructing composite televisi for independently and simult:

in synchronism atleast' two ol lduce from each'scanning sepa nal impulses," means for grou nals representative f the. scanned, and means, for 'contre together offthe ofthe to produce a new series of sign inthe signals .of one original under the control of and du of signals of the' other serie.` being a series of signals rep: scanned area having superir; 'area corresponding to that pc scanned area which initiated nals which served lto nullify 1 signals.

3. In a' system for produc! imposite pictorial image represenindent means for separately and scanning in synchronism a pluareas to produce from each scan- )f signal impulses, means for, assignals representative of the two i areas, and means under'the conthe series'of signals for rendering e means to produce the lsecond is during periods of simultaneously al impulses from both the scan'- develop the controlling series of L'posite television. system, separate synchronously and simultaneousareas to produce from eachl scanendent series of signals represenlight values upon successive eleof each object area, means to asgnals of each independent series composite series of signals reprehe scanned object areas superimea'ns to reduce the normal output one signal producing system under the other signal producing system e with the presence of simultanedsignals in the controlling series veloped in the other signal producnposite television system, separate 1 synchronously and simultaneousareas to produce from each sca-noendent series of signals represenlight values upon successive eleof each object area, means to asignals oi each independent series composite series of 'signals reprethe scanned object areas superimieans to reduce the normal output )f Ione signal producing system. to ider the control of the other signal stem in accordance with the presltaneously produced signals in the ieries of signals developed in the producing system.

hod o! transmittingcomposite telee image signals which comprises inscanning a plurality of related sized iynchronously and simultaneously to i each scanning a series of signals e of the intensity of light and shadlinated elemental areas of each obid'piercing together the signals of ident series into a single series of itrolling the effective intensity of the e of the original series of signals so rolled signal is-reduced to zero value ntrol of the other signal during the '.presence of signals in the controlseries.

thod of transmitting composite telesignals which comprises simultaneig two related object'areas representnd and background along paths cole with the other, producing by each.

nninga series of signalseach reprelntensity ofvllght and shadow upon scanned object area, combining the les of signals 'toform a single series @resentative of both scanned object edu'cing the effective signal intensity f in the combined-l series to zero value ce with the'presence of simultane- :ed signals in the other series.

ithod of composite television transmission which comprises simultaneously and syn- I chronously scanning' a plurality of related size object areas representing the background and foreground areas, producing simultaneously in accordance with the intensity of light and shadow on co-ordinated elemental areas of each separate scanned area an independent series of signals representative thereof, grouping together the plurality of independent series of signals into a single series of signals representative of the light intensity upon the two separate areas transformed into like dimensions and superimposed, and rendering one scanning operation ineffective to produce useful signal representations during each appearance of signal energy output from the other scanning and'under the control thereof so that the singley series pf signals produced from grouping together of the independent series represents an intermingled series of signals representative of like size foreground and background areas superimposed. y

9. The method of transmitting composite television image signals which comprises simultaneously scanning two related object areas representing foreground and background along paths coordinated one with the other, producing by each separate scanning a series of variable character signals each representing the intensity of light and shadow upon the scanned object area, combining the separate series of signals to form a single series of variable character signals representative of both scanned objectareas superimposed, and reducing the signal strength of one series in the combined series to a value at least equal to cut-off in'accordance with the presence of simultaneously produced signals in the other series.

10. In the method of producing signals for television image transmission, the steps which comprise scanning simultaneously -and synchronously two separate object elds of view to produce two separate series of signals each normally different from the other, reducing the energy output representative of one of the independent series during periods of presence of energy impulses exceeding a predetermined threshold value in the other series and under the control thereof, and simultaneously maintaining the energy impulse level of the controlling series at normal value.

1l. In a television system 'the method steps' which comprise producing for spaced background and foreground areas .a plurality of series of energy impulses of electrical characteristics representative of varying values of light' and shadow, each of said series being representative of u one only of the background and foreground areas, combining the independent series to produce a composite series of impulses having electrical characteristics varying in accordance with both background and foreground areas, and reducing the amplitude of the impulses representative of' background to a zero value during periods of.'

simultaneously produced electrical characteristics constituting representations of foreground..

12. In a television systemA the method steps which comprise separately and sychronously scanning background and foreground areas to produce independent series of energy impulses-- of electrical characteristics representative of varying values of light and shadow of the areas scanned, combining the independent series to producea composite series of impulses having electrical characteristics varying in accordance with both the background and foreground areas Scanned, and reducing the effective signal level of the impulses representativeof backgroundtoA cut-off value during periods of .simultaneously .produced signal representations of l foreground;

13. Ina television system the method steps I10 ing intensity 'of light and shadow on elemental areas of the scannedfforeground and background areas, combining the .electric waves, and -upon combining the waves reducing the signal level of one of the electric waves representing one4 area to zero value during time periods where the electric wave representing the other area exceeds a predetermined effective intensity.

L 14. In a picture transmitting system, the method of producing a series of .signals representative of -a plurality vof independent areas scanned which comprises independently and synchronously scanning a plurality of independent areas of similar boundary forms producing from v each scanning independent electric waves of 3U characteristics varying proportionally to light and shade' variations of the scannedv areas, changing thenormal amplitude of one of the electric waves to zero value under the control of the other electric wave-during time periods when the other electric wave exceeds a predetermined amplitude value, and patching together the elec- `tricwaves to form a composite wave character:- istic of the wave which would result from superimposing the independent areas.

15. In combination,I a plurality of simultaneously and synchronously operating scanning systems, means to produce from each scanning system separate series of signals, means for controlling the output energy level from one system 40 between zeroand a finite amplitude in accordance with the output energy level from the other system and solely under the control thereof, and means for assembling the .controlled and controlling series of signals into a single new series of signals representative of the superimposed fields of view scanned by 'the-two scanning. systems. I' 16. The method of producing motion picture lm which comprises independently -scanning a `plurality of object areas toA produce from each scanning a series of electrical signals representative thereof, controlling the energy level Aof one only of the series of electrical signals in accordance With'the presence andabsence o fsignals Ain the other series of electrical signals, de-

veloping from the controlled and controlling.

series of signals a composite series of vsignals representative of the scanned object areassuperimposed, forming, anele'ctro-optical image 60 from the composite seriesof signals, and photographingthe composite electro-optical image to the plurality of scanned 'object areas. 17. The method of transmitting television signals comprising the steps of independently scanning a background and 'a foreground area to pro-Uv ducean independent trainy of energy impulses' lfronreach scanning area according to a 'pre-1.l established `pattern of scanning, equalizing in time relationship the period of production of energy impulses so that the timey duration' of signals resulting from-each scanning is such that' eectivelythe background and foreground areas scanned have equali and similar size boundaries,

.75 combining the separate energy impulses, nullifying the effect oi' one of the se: pulses in accordance with the; impulses in the other series an( resultant combination of ene nals. j

18. In television apparatus wl and foreground areas are indep means for synchronously scann to produce independent video i ing the foreground and backgrc to' co-ordinate in time relation of each of the' produced serie means for reducing the signal .l of signals representingthe bach ing time periods of presence -.vision image signals which con ently and separately scanning Va a foreground area-synchronously each scanning a series of signe of each scanned area, utilizing duced series of signals to contro other series during periods of pre trolling signal, and adding to tl ries of signals the resultant coi signals.

21. Thel method of producing vision image signals which coi nously producing two separate trains of signal energy, and au vpressing to a predetermined di tralnsof signal energy only d presence df theother train of s: under the control thereof irrespl plitude values thereof exceeding threshold value. p

22.. The method of producing .vision image signals Awhich co1 lnously producing -two separate trains of signal energy, automati to a predetermined degree one of nal energy representlngthe inde areas only during periods of pr in .the other train of signal enen control' thereof irrespective oi values thereof. exceeding a prede produce a motion picture 1flrn representative dft',

oldyvalue, and adding Vto the: of signals theresultantcontrol] nals'. i 23. The method of producing' representative of spaced foregr ground areaswhich comprises t] ning' at least one vbackground ouslyand synchronously scann foreground area of dimensions s the scanned background, produ'ci `ningsimage signals representati sities of lights and shadows on a controlling the'signal level of tl awasvo g to produce a new series of sig--` itive of a scanned background posedl thereon any scanned forehod of producing composite tele- ,which comprises independently usly scanning a plurality of image L at least one represents a-backroducing from 'each scanning a seige signals representative of the scanned area,

scanned areas, reducing the intensity of the signals representative of the background area under the control of one of the other simultaneously produced signals representative of another and adding together, subsequent to the intensity reduction of the background. area signals, all of the resultant signals to produce a new series of signals representative of all scanned areas superimposed.

2 5. The method claimed in the preceding claim comprising the additional step of producing from the last named series of signals an electrooptical image representation of thebackground area.' having superimposed thereon any scanned foreground area.

- ALFRED N.- GOLDSMITH.

THADDEUSR. GOLDSBOROUGH. 

